Electron discharge device



Dec. 1, 1936. A. L. SAMUEL 2,052,334

ELECTRON DISCHARGE DEVICE Filed Oct. 27, 1934 2 Sheets-Sheet 1 INVENTORALSAMUEL BY y A T TORNE V Dec. 1, 1936. A, A L 2,062,334

ELECTRON DISCHARGE DEVICE Filed Oct. 2'7, 1934 2 Sheets-Sheet 2 INVENTORY B ALSAMUEL OMZmJdwL ATTORILEY Patented Dec. 1, 1936 UNITED STATES-ELECTRON DISCHARGE DEVICE Arthur L. Samuel, Orange, N. J., assignor toBell Telephone Laboratories,

York; N. Y., a corporation of New York Incorporated, New

Application October 27, 1934, Serial No. 750,287 17 Claims. (01.25041.5)

This invention relates to electron discharge devices and moreparticularly to such devices of the pentode type adapted for theamplification of ultra-high frequency impulses.

' One object of this invention .is to amplify efliciently ultra-highfrequency currents and voltages.

Another object of this invention is to shield effectively the input andoutput electrodes and leading-in conductors in an electron dischargedevice from each other.

A further object of this invention is to simplify thestructure ofelectron discharge devices having a plurality of individual electrodeunits within a single enclosing vessel.

In one embodiment of this invention, an electron discharge devicecomprises an enclosing vessel having a plurality of pentode units. Eachof the pentode units comprises a cathode, an anode,

go a control electrode between the anode and the cathode, a shieldelectrode, and a suppressor electrode. Each of the shield and suppressorelectrodes includes a wire or perforate or grid portion disposed betweenthe control electrode and the anode of the respective pentode units andhas secured thereto a metallic disc or plate extending between theseveral electrode units and to immediately adjacent the side walls ofthe enclosing vessel. The plates or discs electrically :0 connect theshield and suppressor electrodes of the several electrode units and aredisposed closely adjacent to form a condenser coupling the screen andsuppressor electrode. The discs or plates also serve as screens toeffectively shield 35 the anodes and the leading-in conductors thereforfrom the control electrodes and the leadingin conductors therefor.

The discharge device preferably is mounted in a metallic partitiondisposed substantially oo- 40 planar with the discs or plates andcapacitively coupled thereto, the partition preferably being grounded.

The invention and the features thereof will be understood more clearlyand fully from the fol- 45 lowing detailed description with reference tothe accompanying drawings in which:

Fig. 1 is a perspective view of an electron discharge deviceillustrative of this invention, portions of the enclosing vessel beingbroken away to show the electrode assemblies more clearly;

Fig. 2 is an elevational view of the electron discharge device shown inFig. 1 together with an external shield in alignment with the internal55 metallic discs or plates;

Fig. 3 is a detail view of the control electrode assembly included ineach of the electrode units;

Fig. 4 is another detail view showing the construction of the screen orshield electrodes;

Fig. 5 is a fragmentary view showing an al- 5 temative form for a screenor shield electrode;

Fig. 6 is a cross-sectional view of an electrode unit along. line 6-6 ofFig. 2 showing the configuration and relative disposition of theelectrodes; '10

Fig. 7 is a schematic view illustrating one gen- ,eral circuit includingan electron discharge device constructed in accordance with thisinvention;

Fig. 8 is a perspective view of an electron dis- 15 charge deviceillustrative of another embodiment of this invention in which a separateshield is provided for segregating the leading-in conductors forthe'anodes from the leading-in conductors for the control electrodes andthe cathodes; 20

Fig. 9 is a top view of the electrode assembly in the device shown inFig. 8; and

Fig. 10 is a cross-sectional view of the electrodes showing theconfiguration and relative disposition thereof along the line l0-lli of5 Fig. 8.

Referring now to the drawings} the electron discharge device shown inperspective in Fig. 1 and schematically in Fig. 7, comprises anenclosing vessel having a cylindrical portion l0 and substantially planeend walls II and I2. Enclosed within the vessel are two electrode unitseach-of which includes a cathode IS, an anode l4,,a control electrode I5 between the cathode and the anode, and a shield electrode l6 and asuppressor electrode ll disposed between the control electrode and theanode. The electrodes in each unit are coaxially arranged and the twounits may be disposed parallel to each other. Preferably, the electrodesin each unit are disposed as closely 40 adjacent as is mechanically andelectrically feasible.

Each cathode comprises a linear filament l9, which may be of thoriatedtungsten, supported at one end by a flexible inverted J-shaped member orwire 20 extending from a rigid metallic support or rod 2| sealed in theendwall I2 of the enclosing vessel. The filaments iii are secured attheir other end to a rigid M-shaped metallic member or wire 22 carriedby a metallic support or rod 23 also sealed in the end wall I2 01' theenclosing vessel. The anode l4 ofea'chelectrode unit includes twosections, each having an armate portion 24 and a large surface flange25. The flanges 25 are secured together in face-to-face relation byintegral bent-over tabs 26 on one flange extending through apertures 21in the other flange, so that the arcuate portions 24 form asemi-cylinder which is coaxially disposed about the correspondingfilament [9. Each anode is supported by a rigid metallic rod or wire- 28secured to the flanges 25 and sealed in the end wall H of the enclosingvessel. Each of the control electrodes [5, as clearly shown in Fig. 3,comprises two large area plates 29 secured together in face-to-facerelation by integral bent tabs 30 on one plate extending throughapertures 3| in the other plate. The plates 29'are provided at one endwith outwardly bent flanges 32 to which each turn of a helical grid 33is secured, for example, by welding. As clearly shown in Fig. 6, eachgrid 33 encompasses a corresponding filament l9 and is coaxialtherewith. The control electrodes l5 are individually supported bymetallic rods or wires 34 sealed in the end wall l2 of the enclosingvessel.

The control electrodes are each encompassed by a shield electrode which,as shown in Fig. 4, comprises a pair of parallel supporting wires 35carrying a plurality of U-shaped wires 36 which are disposed parallel toone another and are secured to the wires 35 in any suitable manner, forexample by welding. As shown in Fig. 6, the U- shaped wires 36 extendthrough an aperture in a metallic plate or disc 3'! and are bent over attheir ends, the wires 35 being secured to the plate or disc 3'! as bywelding. The plate or disc 31 extends to immediately adjacent the innerwall of the cylindrical portion in of the enclosing vessel and issupported by a single rigid rod or wire 38, which abuts against the discand carries a wire stub 39 secured to the plate or disc, sealed in theend wall of the enclosing vessel. The disc or plate3'l together with thewire grids 36 form an assembly which serves as a shield between thecontrol electrodes l5 and the anodes l4 and hence segregate theseelectrodes and the leadingin conductors 34 and 28, respectively,therefor so that the device may be operated eificiently at ultra-highfrequencies. I

In an alternative construction the shield electrodes may be made bypunching holes 40 in a sheet and then bending it into a U shape as shownin Fig. 5. If desired, the grid shown in Fig. 5 may be formed integrallywith the plate.

Disposed between each, shield electrode and anode is a suppressorelectrode which may be of the same general construction as the shieldelectrodes shown in Figs. 4- and 5. Each suppressor electrode comprisesa U-shaped perforate or wire portion 4! extending through an aperture ina plate or disc 42 and secured to parallel wires 43 which are suitablysecured, as by welding, to the plate or disc 42. The plate or disc 42 isdisposed parallel to the plate or disc 31 and coextensive therewith, andis supported by a single wire or rod 44 sealed in the end wall 12 of theenclosing vessel and carrying a stub 45 secured, as by welding, to thedisc or plate 42. The plates or discs 31 and 42 are maintained inparallel spaced relationship by a plurality of insulators 46 to whichtabs 47 and 48 integral with the plates or discs 31 and 42,respectively, are secured by wires 49, and form a condenser coupling theshield and suppressor electrodes. The disc or plate 42 is electricallyconnected to one end, preferably the negative or grounded end, of thefilaments l9 by a wire 59 secured to the M-shaped member 22, and henceserves to increase the shielding between the conaooasss trol electrodesl5 and anodes l4 and the leadingin conductors 34 and 29, respectively,therefor;

In order to further increase the shielding between these elements, anapertured external metallic member or shield 5| may be provided, themember or shield 5| extending from immediately adjacent the wall III ofthe enclosing vessel and being disposed substantially coplanar with theplates or discs 31 and 42.

A metallic disc 52 carrying-a getter material 58, such as magnesium, issupported bya short wire or rod 53 sealed in the end wall ll of theenclosing vessel at a point remote from the electrodes. After theelectrodes of the device have been out-gassed and the enclosing vesselsealed, the getter may be flashed, as by high frequency inductionheating, to fix residual gases within the enclosing vessel.

In one typical circuit, illustrated in Fig. 'l, in which the two pentodeunits of devices of the construction described hereinabove are connectedin push-pull, the control, electrodes |5 may be connected to oppositeends of the secondary winding 54 of an input transformer T1, the centerof the secondary being connected tothe negative terminal of a suitablepotential source. The anodes I4 may be connected similarly to oppositeends of the primary winding 55 of an output transformer T2, the centerof the primary 55 being connected to the positive terminal of a suitablepotential source. A suitable positive potential, less than the anodepotential, is applied to the shield electrodes I6.

The secondary winding 54 and the primary winding 55 may be shunted byfixed or variable condensers 56 and 51, respectively. Alternative- 1y,one or both .of these condensers may be omitted, depending upon thefrequency at which the device is intended to operate and thecharacteristics of the input and output circuits.

In; another embodiment of this invention shown in Fig. 8, the twopentode units are disposed with their longitudinal axes substantiallyparallel to the longitudinal axisof the enclosing vessel In, thecathodes and grid electrodes being maintained in proper positionrelative to each other by spaced insulating members 59 and 60. Theinsulating members 59 and 60 are supported by a metallic upright or rod6i sealed in the end wall l2 of the enclosing vessel and are maintainedin the proper relation by bent wires 62 and 63 secured to the upright orrod 6| and extending through the insulating members 59 and 60,respectively.

Each of the pentode units includes a helical filamentary cathode 64which is secured at one end to a tie wire 65 upon the insulating member59 and secured to the upright or rod BI, and which is secured at theother end to a corresponding rod or wire 66 sealed in the end wall l2 ofthe enclosing vessel. Two control electrodes, which maybe of the samegeneral construction shown in Fig. 3 are associated individually withthe corresponding cathodes 64 and are supported individually by rods orwires 61 extending through the lower insulating member 60 and sealed inthe end wall I 2 of the enclosing vessel.

The control electrodes are encompassed in common by a shield or screengrid assembly including parallel metallic plates 68 and U-shaped endportions which may comprise a plurality of U-shaped wires 69 secured, asby welding, to rigid uprights or wires 10. The uprights or wires I0 aresecured to the plates 68 and extendthrough the insulating members 59 and60, thereby maintaining the end portions 69 in proper position,

. preferably coaxial, with respect to the cathodes 68 and control grids33. As shown clearly in Fig. 9 corresponding of the uprights or rods 70may be electrically connected by short wires or stubs H which areconnected in turn to a tie wire l2 secured to a leading-in conductor 13sealed in the end wall ll of the enclosing vessel.

The shield or screen electrode assembly is encompassed by a similarlyshaped suppressor electrode assembly including metallic plates '74disposed parallel to each other and to the plates 68, and U-shaped endportions, comprising spaced U-shaped wires 15, coaxial with thecorresponding cathode 64 and control grid 33. The wires 15 are secured,as by welding, to uprights or rods 16 secured to the plates 14 andextending through the insulating members 59 and 60. The suppressorelectrode assembly may be connected electrically to the cathodes 64 bythe wire 62 which may be suitably secured, as by welding, to one of theplates 14.

As shown clearly in Fig. 9, the insulating member 59 may be providedwith slots 11 extending between corresponding of the uprights or rods 10and 15, thereby increasing the insulating path therebetween. In order toallow lateral expansion and contraction of the shield and suppressorelectrode assemblies, the insulating member 59 is provided with acut-out portion forming bearing or guiding surfaces 18 for the uprightsor rods 10 adjacent one end of the shield electrode assembly, andforming other hearing or guiding surfaces 79 for the uprights or rods 16adjacent the same end of the suppressor electrode assembly. The cut-outportion is formed also to provide shoulders 80 limiting outward movementof the uprights or rods 16 thereadjacent.

Each of the pentode units includes an anode comprising a substantiallysemi-cylindrical portion 8| coaxial with the corresponding cathode 64,and outwardly extending flanges 82 and 83 which increase the rate ofheat radiation from the anodes and thereby maintain them at a safetemperature during operation of the device. The anodes are supportedindividually by metallic rods or wires 84 which serve as leading-inconductors and are sealed in the end wall ll of the enclosing vessel.

In order to segregate the anode and control electrode leading-inconductors more completely, a shielding disc 85 is provided; the dischaving a flange 86 immediately adjacent the side Wall of the enclosingvessel. The disc 85 rests upon the insulating member 60 and may beelectrically connected to the suppressor electrode by a bent wire 8'!which may be secured, as by welding, to one of the plates 74 and one ofthe rods 76.

Suitable apertures are provided in the disc 85 for allowing free passageof the cathodes 64, grid supporting rods 61, and the uprights 10.

The device may be mounted in a metallic partition 5| similarly to thedevice shown in Fig. 3, the partition being disposed substantiallycoplanar with the disc 85.

A metallic disc 52 is supported below the disc 85 by a short wire 88 andcarries a quantity of getter material, such as a strip of magnesium 58,for fixing residual gases in the enclosing vessel.

Although specific embodiments have been shown and described, it will beunderstood, of course, that modifications may be made therein withoutdeparting from the scope and spirit of this invention as defined in theappended claims.

What is claimed is:

1. An electron discharge device comprising a said cathode and said anodeforming a condenser coupling said electrode portions.

2. An electron discharge device comprising a cathode, a controlelectrode surrounding said cathode, an anode, a plurality of gridelectrode elements disposed between said cathode and said anode, and aplurality of plate members individually secured to said electrodeelements and spaced to form a condenser coupling said electrodeelements, one of said plates also extending across the device andserving also as shield.

3. An electron discharge device comprising a cathode, an anode, acontrol grid between said cathode and anode, a plurality of arcuategrids disposed between said anode and control grid, and parallelmetallic plate members extending from said arcuate grids and eachindividually associated electrically with a corresponding one of saidarcuate grids, said plate members forming a condenser coupling saidgrids.

4. An electron discharge device comprising a plurality of metallicmembers spaced to form a condenser, shield and suppressor gridsindividually secured to said metallic members, and a cathode, a controlelectrode, and an anode in cooperative relation to said grids.

5. An electron discharge device comprising a plurality of electrodeunits each including a cathode, an anode, and a plurality of gridelectrodes between said cathode and anode, and metallic membersconnecting two grid electrodes of one unit with the corresponding gridelectrodes of another unit, said metallic members being disposedadjacent one another to form a condenser.

6. An electron discharge device comprising a plurality of electrodeunits each including a cathode, an anode coaxial with said cathode, anda plurality of grid electrodes between said cath- 1 8. An electrondischarge device comprising a plurality of cathodes, a plurality ofanodes each disposed in cooperative relation to a corresponding one, ofsaid cathodes, and a plurality of hollow metallic members encompassingsaid cathodes in common, each of said members having a grid portionbetweeneach cathode and the corresponding anode and having a plateportion connecting said grid portions, the plate portions of saidmembers being disposed adjacent each other to form a condenser.

9. An electron discharge device comprising a plurality of electrodeunits each including a cathode, an anode, and acontrol electrodedisposed between the anode and cathode, and a metallic shield memberextending between said units and trade and the anode correspondingthereto.

10. An electron discharge device comprising a plurality of electrodeunits each including a cathode and an anode, a plurality of spacedmetallic shield members extending between said units, and a plurality ofgrids carried by each of said shield members, each of said grids beingdisposed between -a corresponding cathode and anode.

11. An electron discharge device comprising a plurality of electrodeunits each including a cathode, a control electrode, a screen electrode,a. suppressor electrode, and an anode, means electrically connecting thescreen electrodes of said units, and means electrically connecting thesuppressor electrodes of said units, said first and second meansbeing-cooperatively associated to form a. condenser.

12. An electron discharge device comprising a pair of parallel metallicplates forming a condenser, a plurality of grids carried by each of saidplates, the grids on the two plates being arranged in cooperative pairs,and an anode, a cathode and a control electrode cooperatively disposedwith respect to each of said cooperative pairs of grids.

13. An electron discharge device comprising a plate member having aplurality of. apertures therein, a U-shaped perforate electrode adjacenteach of said apertures and carried by said plate member, another platemember disposed adjacent said first plate member and having apertures inalignment with said first apertures, a U-shaped grid adjacent each ofsaid second apertures and carried by said second plate, said platemembers forming a condenser, a cathode and a grid electrode within eachof said grids, and an anode disposed adjacent each of said U shapedperforate electrodes.

14. In combination, an electron discharge de- 2,062,884 having a gridportion between each control elecvice comprising an enclosing vessel, acathode, an-input electrode, an output electrode, and a metallic membershielding said input electrode from said output electrode and extendingadjacent walls of said enclosing vessel, and an external metallic shieldsurrounding said walls and disposed with its inner edge close to saidme'-- tallic member.

15. In combination, an electron discharge device comprising an enclosingvessel, a metallic disc within said vessel and extending to immediatelyadjacent opposite walls thereof, said disc having an aperture therein, agrid carried by said disc and overlying said aperture, a cathode and acontrol electrode adjacent one surface of said grid, an anode adjacentthe opposite surface or said grid, and leading-in conductors for saidanode and said control electrode extending from opposite ends of saidvessel, and a metallic member encompassing said vessel and disposed withits inner edge inthe vicinity of said metallic disc. 16. An electrondischarge device comprising-a pair of spaced insulating members, aplurality of plate members spaced to form a condenser between saidinsulating members, and maintained in position thereby, and a pluralityof electrodes individually supported by and electrically connected tosaid plate members.

17. An electron discharge device comprising a pair of spaced insulatingmembers, a plurality of hollow metallic members disposed one withinanother, between said insulating members and supported thereby, each ofsaid metallic members including perforate end portions and intermediateplate portions, said plate portions being spaced to form a condenser,and a plurality of cathodes extending between said plate members anddisposed adjacent said perforate end portions.

ARTHUR L. SAMUEL.

